You need to learn how to search this forum, as it contains a lot of usefull information viewtopic.php?t=2974
The logs will provide usefull info in most cases, so always check them for errors. ( /var/log/)
To check mysql issues have a look at viewtopic.php?t=2938

tesme33,
Did you read the topics mentioned?
You did mention "I now even have the feeling that the error comes more often." after you increased memory to 8GB.
As feelings and facts are two different things, you could try to explain that feeling by posting the error messages and the efa version used.
You also mentioned that "some tables, incl. sqlgray, need repair." Can you explain why?

About mysql: Install mysqltuner as mentioned in the above topics and post the mysqltuner output and the errors from the mysql err file.

Hi
yes i was reading them. Feeling means i didnt meassure the exact time between the emails.
Before the Memory upgrade i had the issue perhaps once per day and yesterday i had the email 4 times.
According to the .err log the db is regularly shutting down.

Why some tables needed a repiar is not know to me but it might be that there was an undetected reboot.

170326 14:08:25 [ERROR] Missing system table mysql.proxies_priv; please run mysql_upgrade to create it
170326 14:08:25 [ERROR] Native table 'performance_schema'.'events_waits_current' has the wrong structure
170326 14:08:25 [ERROR] Native table 'performance_schema'.'events_waits_history' has the wrong structure
170326 14:08:25 [ERROR] Native table 'performance_schema'.'events_waits_history_long' has the wrong structure
170326 14:08:25 [ERROR] Native table 'performance_schema'.'setup_consumers' has the wrong structure
170326 14:08:25 [ERROR] Native table 'performance_schema'.'setup_instruments' has the wrong structure
170326 14:08:25 [ERROR] Native table 'performance_schema'.'setup_timers' has the wrong structure
170326 14:08:25 [ERROR] Native table 'performance_schema'.'performance_timers' has the wrong structure
170326 14:08:25 [ERROR] Native table 'performance_schema'.'threads' has the wrong structure
170326 14:08:25 [ERROR] Native table 'performance_schema'.'events_waits_summary_by_thread_by_event_name' has the wrong structure
170326 14:08:25 [ERROR] Native table 'performance_schema'.'events_waits_summary_by_instance' has the wrong structure
170326 14:08:25 [ERROR] Native table 'performance_schema'.'events_waits_summary_global_by_event_name' has the wrong structure
170326 14:08:25 [ERROR] Native table 'performance_schema'.'file_summary_by_event_name' has the wrong structure
170326 14:08:25 [ERROR] Native table 'performance_schema'.'file_summary_by_instance' has the wrong structure
170326 14:08:25 [ERROR] Native table 'performance_schema'.'mutex_instances' has the wrong structure
170326 14:08:25 [ERROR] Native table 'performance_schema'.'rwlock_instances' has the wrong structure
170326 14:08:25 [ERROR] Native table 'performance_schema'.'cond_instances' has the wrong structure
170326 14:08:25 [ERROR] Native table 'performance_schema'.'file_instances' has the wrong structure
170326 14:08:25 [ERROR] Incorrect definition of table mysql.event: expected column 'sql_mode' at position 14 to have type set('REAL_AS_FLOAT','PIPES_AS_CONCAT','ANSI_QUOTES','IGNORE_SPACE','IGNORE_BAD_TABLE_OPTIONS','ONLY_FULL_GROUP_BY','NO_UNSIGNED_SUBTRACTION','NO_DIR_IN_CREATE','POSTGRESQL','ORACLE','MSSQL','DB2','MAXDB','NO_KEY_OPTIONS','NO_TABLE_OPTIONS','NO_FIELD_OPTIONS','MYSQL323','MYSQL40','ANSI','NO_AUTO_VALUE_ON_ZERO','NO_BACKSLASH_ESCAPES','STRICT_TRANS_TABLES','STRICT_ALL_TABLES','NO_ZERO_IN_DATE','NO_ZERO_DATE','INVALID_DATES','ERROR_FOR_DIVISION_BY_ZERO','TRADITIONAL','NO_AUTO_CREATE_USER','HIGH_NOT_PRECEDENCE','NO_ENGINE_SUBSTITUTION','PAD_CHAR_TO_FULL_LENGTH'), found type set('REAL_AS_FLOAT','PIPES_AS_CONCAT','ANSI_QUOTES','IGNORE_SPACE','NOT_USED','ONLY_FULL_GROUP_BY','NO_UNSIGNED_SUBTRACTION','NO_DIR_IN_CREATE','POSTGRESQL','ORACLE','MSSQL','DB2','MAXDB','NO_KEY_OPTIONS','NO_TABLE_OPTIONS','NO_FIELD_OPTIONS','MYSQL323','MYSQL40','ANSI','NO_AUTO_VALUE_ON_ZERO','NO_BACKSLASH_ESCAPES','STRICT_TRANS_TABLES','STRICT_A
170326 14:08:25 [ERROR] Event Scheduler: An error occurred when initializing system tables. Disabling the Event Scheduler.
2017-03-26 14:12:37 140464932476960 [ERROR] Missing system table mysql.roles_mapping; please run mysql_upgrade to create it
2017-03-26 14:16:29 140336478096128 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-03-26 14:16:29 140336478096128 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-03-26 14:16:29 140336478096128 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-03-26 14:16:30 140336478096128 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-03-26 14:45:11 140336477793024 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-03-31 17:42:59 140648105954048 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-03-31 17:43:00 140648105954048 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-03-31 17:43:00 140648105954048 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-03-31 17:43:01 140648105954048 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-03-31 18:20:30 140648105650944 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-04-14 19:19:26 140693330893568 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-04-14 19:19:27 140693330893568 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-04-14 19:19:27 140693330893568 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-04-14 19:19:27 140693330893568 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-04-14 19:25:40 140693331196672 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-04-28 19:23:02 140510100003584 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-04-28 19:23:03 140510100003584 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-04-28 19:23:03 140510100003584 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-04-28 19:23:03 140510100003584 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-04-28 22:18:06 140510100609792 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-05-12 20:10:27 140515427748608 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-05-12 20:10:27 140515427748608 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-05-12 20:10:27 140515427748608 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-05-12 20:10:27 140515427748608 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-05-12 20:44:07 140515427445504 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-05-26 20:08:59 139628532660992 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-05-26 20:09:00 139628532660992 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-05-26 20:09:00 139628532660992 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-05-26 20:09:00 139628532660992 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-05-26 20:28:17 139628532054784 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-06-09 21:44:35 139630541961984 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-06-09 21:44:36 139630541961984 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-06-09 21:44:36 139630541961984 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-06-09 21:44:36 139630541961984 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-06-09 21:51:51 139630541658880 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-06-23 22:32:04 140396144810752 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-06-23 22:32:05 140396144810752 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-06-23 22:32:05 140396144810752 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-06-23 22:32:06 140396144810752 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-06-23 22:33:38 140396144507648 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-07-07 23:19:25 139859971853056 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-07-07 23:19:26 139859971853056 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-07-07 23:19:26 139859971853056 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-07-07 23:19:26 139859971853056 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-07-08 2:54:03 139859971549952 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-07-22 0:06:14 140207638194944 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-07-22 0:06:15 140207638194944 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-07-22 0:06:15 140207638194944 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-07-22 0:06:15 140207638194944 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-07-22 1:15:07 140207638498048 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-08-05 0:53:58 140028170189568 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-08-05 0:53:59 140028170189568 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-08-05 0:53:59 140028170189568 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-08-05 0:53:59 140028170189568 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-08-05 3:14:01 140028170795776 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-08-19 1:40:47 140100628957952 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-08-19 1:40:48 140100628957952 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-08-19 1:40:48 140100628957952 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-08-19 1:40:49 140100628957952 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-08-19 3:00:37 140100629261056 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-09-02 2:28:15 139823726934784 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-09-02 2:28:15 139823726934784 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-09-02 2:28:15 139823726934784 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-09-02 2:28:16 139823726934784 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-09-02 2:54:23 139823726328576 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-09-16 3:15:47 139666399963904 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-09-16 3:15:47 139666399963904 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-09-16 3:15:47 139666399963904 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-09-16 3:15:48 139666399963904 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-09-16 3:22:56 139666399660800 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-09-30 4:03:24 140334564993792 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-09-30 4:03:25 140334564993792 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-09-30 4:03:26 140334564993792 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-09-30 4:21:19 140334564690688 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-10-14 4:50:36 140199296629504 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-10-14 4:50:37 140199296629504 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-10-14 4:50:37 140199296629504 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-10-14 4:50:38 140199296629504 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-10-14 6:08:05 140199296326400 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-10-28 5:37:14 139644172790528 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-10-28 5:37:15 139644172790528 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-10-28 5:37:15 139644172790528 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-10-28 5:37:16 139644172790528 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-10-28 6:08:59 139644172487424 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-11-11 5:24:28 140064131599104 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-11-11 5:24:28 140064131599104 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-11-11 5:24:28 140064131599104 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-11-11 5:24:29 140064131599104 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-11-11 6:07:39 140064130992896 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-11-25 5:28:26 139852443978496 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-11-25 5:28:27 139852443978496 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-11-25 5:28:27 139852443978496 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-11-25 5:28:27 139852443978496 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-11-25 6:06:01 139852444281600 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-12-09 6:15:42 140352427752192 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-12-09 6:15:43 140352427752192 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-12-09 6:15:43 140352427752192 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-12-09 6:15:44 140352427752192 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-12-09 7:02:36 140352427449088 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2017-12-23 7:02:47 140219395824384 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2017-12-23 7:02:48 140219395824384 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2017-12-23 7:02:48 140219395824384 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2017-12-23 7:02:48 140219395824384 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2017-12-23 7:06:28 140219395521280 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2018-01-06 7:01:36 139684808022784 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2018-01-06 7:01:36 139684808022784 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2018-01-06 7:01:36 139684808022784 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2018-01-06 7:01:37 139684808022784 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2018-01-06 7:02:06 139684807719680 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2018-01-20 7:49:24 140257093176064 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2018-01-20 7:49:24 140257093176064 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2018-01-20 7:49:25 140257093176064 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2018-01-20 7:49:25 140257093176064 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2018-01-20 8:08:51 140257092569856 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2018-02-03 8:35:37 140089961061120 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2018-02-03 8:37:01 140089961061120 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2018-02-03 8:37:01 140089961061120 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2018-02-03 8:37:02 140089961061120 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2018-02-03 8:37:02 140089961061120 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2018-02-17 9:25:43 140610730400512 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2018-02-17 9:25:43 140610730400512 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2018-02-17 9:25:44 140610730400512 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2018-02-17 9:25:44 140610730400512 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2018-02-17 10:09:31 140610730097408 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2018-03-03 10:16:25 140675356687104 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2018-03-03 10:16:26 140675356687104 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2018-03-03 10:16:26 140675356687104 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2018-03-03 10:16:26 140675356687104 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2018-03-03 11:18:25 140675356080896 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2018-03-17 11:03:40 139883142490880 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2018-03-17 11:03:40 139883142490880 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2018-03-17 11:03:41 139883142490880 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2018-03-17 11:03:41 139883142490880 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2018-03-17 11:36:23 139883142187776 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2018-03-31 12:46:50 139896396401408 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2018-03-31 12:46:51 139896396401408 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2018-03-31 12:46:51 139896396401408 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2018-03-31 12:46:52 139896396401408 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2018-03-31 14:13:11 139896396098304 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2018-04-14 13:32:00 140621161290496 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2018-04-14 13:32:00 140621161290496 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2018-04-14 13:32:01 140621161290496 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2018-04-14 13:32:01 140621161290496 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2018-04-14 15:00:00 140621161593600 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2018-04-28 14:19:47 140107271125760 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2018-04-28 14:19:48 140107271125760 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2018-04-28 14:19:49 140107271125760 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2018-04-28 14:19:49 140107271125760 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2018-04-28 18:48:10 140107270822656 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2018-05-12 15:06:57 139903362689792 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2018-05-12 15:06:57 139903362689792 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2018-05-12 15:06:58 139903362689792 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2018-05-12 15:06:58 139903362689792 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2018-05-12 15:28:46 139903362386688 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired
2018-05-28 15:47:11 139746730797824 [ERROR] mysqld: Table './sqlgrey/from_awl' is marked as crashed and should be repaired
2018-05-28 15:47:12 139746730797824 [ERROR] mysqld: Table './sqlgrey/domain_awl' is marked as crashed and should be repaired
2018-05-28 15:47:12 139746730797824 [ERROR] mysqld: Table './sqlgrey/connect' is marked as crashed and should be repaired
2018-05-28 15:47:12 139746730797824 [ERROR] mysqld: Table './sqlgrey/config' is marked as crashed and should be repaired
2018-05-28 16:02:39 139746730494720 [ERROR] mysqld: Table './efa/tokens' is marked as crashed and should be repaired

The errors mentioned in ERROR in .err are from 2017-03-26 till 2018-05-28. You had some serious issues back then. Upgrade went wrong?

In the log: 2019-02-23 1:20:03 139914126166048 [Note] InnoDB: innodb_empty_free_list_algorithm has been changed to legacy because of small buffer pool size. In order to use backoff, increase buffer pool at least up to 20MB.

Will do, Yes I have been getting them - to be fair the box with the errors is probably 100 times busier than the one that doesn't. If I recall correctly it happened after an update. It's quite random and more than anything it's just annoying - the volume of email it generates
One email contains:
SQLgrey established connection to: DBI:mysql:database=sqlgrey;host=localhost
The other is:
SQLgrey encountered an SQL error and triggered a reconnection to: DBI:mysql:database=sqlgrey;host=localhost

Hi
today i had time to implement the mentioned steps.
Now lets see if the behaviour will change. But anyhow thanks for the good and helpful feedback.

I have not done any manual change in the EFA VM, expect the normal configuration and SASL auth for external mailservers, and i started with EFA3.0.0.? This might be the difference between your amount of tables and mine.

But isn't it dangerous to set /tmp as tempdir for the database ? Especially as i only have 1GB there ?

Looking into /var/EFA/backup i see that the ERRORS start dates match the the upgrade to 3.0.1.9 in March 2017. But the restart messages i only get since august 2018. Might be that some tables got full.

Hi
sorry. I ment the steps you proposed to update the server configuration. And now the db seems to be stable.
At least i dont see shutdowns. But nevertheless i get the reconnect error emails. Just had 3 reconnects at 16:37 (local time) within one minute.

Optimazation is done, as the system is not under heavy load.
I would assume thats the reason why my reconnects are not so often as for efranko.

I realized that the error (sqlgray reconnects) happened exactly when a message came in and mailScanner was running:

The caveats come with the data you have in the DB and the charset it was put in as and what the charset is when you take it out and frankly it's a minefield. This extends to the newer versions as well and when you make the database and connection charset changes all sorts of weird things may happen when the DB tries to compare pre-change records with post-change ones; what was valid UTF8 may now be read as ASCII single-byte garbage and will lead to trouble.